Alternative switching strategies for future integrated DOD voice and data networks are studied. Three fundamental problems are addressed: (1) The economics of integrating voice and data applications in a common communication system; (2) the comparison of alternative switching technologies for integrated voice and data networks; (3) the economics of low voice digitization rate devices. Strategies examined are traditional, fast, and ideal circuit switching, hybrid (circuit-packet) switching, and packet switching. These strategies are examined in conjunction with a data base representing future Defense Department voice and data requirements. The major conclusion is that packet switching is substantially more cost-effective for serving these voice or data requirements than the other alternatives examined. The sensitivity of the results are tested with respect to traffic variations, cost trends of switching and transmission, and network performance variables. The significant variables which affect the conclusions are identified and quantified.